Color dots in the image

Hi, I have a problem with the image of the microscope. A strange color pattern appears in the outside borders of the image. Cleaned the lens multiple times, blowed it too (to discard it’s dust). Also checked the RAW of an image: seems everything okay. Any ideas?


The image shows the dot pattern without any sample and without illumination (forum doesn’t let me upload more than one image, I’ll try to upload two more as comments).
I’m using the RPi camera v2.1
Any ideas? Thanks in advance.


In this capture I used a leaf as a sample and Illumination.


Another screenshot with better resolution of the leaf. The dot pattern it’s the same.

This looks like a calibration issue, a different version from the green thread that you have also posted in.
It would be worth trying the recent beta release of the software Software Beta release - Announcements - OpenFlexure Forum. The calibration function has had a major revision and does not have these failure modes that the old version had.
You can revert to the normal release afterwards with sudo ofm upgrade to get back onto the stable version. The calibration should remain when you revert.

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Hi WilliamW, thanks for your fast answer. I updated yesterday to the latest beta - without any changes. Any ideas?
Anyway, to check if it’s properly updated, how can I know if I updated to the latest beta?

I assume that you re-calibrated after the upgrade? The version will show up in the webapp in the about tab. It will end with ‘b’ for beta. I would expect the re-calibration to get rid of the ‘green centre-pink edges’ even if the dots stay. In the new beta the disable flat field correction button will remove the flat colour calibration. What does the image look like 1 - after re-calibration, 2 - with flat-field correction disabled?

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Thanks for the hints. I managed to recalibrate it; then it gets a green color image. I updated to the beta version (wasn’t updated). Then recalibrated again. After a few tries, and using a white paper, I managed to calibrate it well! Thanks for everything.

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